Considering its eminence in Mexican cuisine, salsa roja has a curiously modest name. It translates prosaically as “red sauce,” but that moniker fails to convey the zippy tomato-and-chile-based sauce’s ability to elevate so many foods: nachos, tacos, or quesadillas; fried eggs, potatoes, grilled chicken, or steak. I’m such a fan that I always need a batch in my refrigerator so that I have some at the ready whenever the mood strikes.
Salsa roja is made with tomatoes, a fresh chile (or several), onion, cilantro, and possibly garlic and dried chiles. Some or all of the ingredients are cooked, at least briefly, and the sauce is blended. It sounds straightforward, but there’s a fascinating amount of variation among recipes.
Some cooks char and blister the ingredients, while others cover them with water and boil them for as long as 30 minutes. Some cooks use a Mexican mortar and pestle (known as a molcajete) for rustically chunky results, while others use a blender for a smoother consistency. The heat level can vary from relatively mild to perilously spicy, making it advisable to approach any salsa roja with respectful caution.
In a recipe that varies so much, the presence of tomatoes and fresh chiles was reassuringly universal. I chose to use plum tomatoes for their meatiness and a single jalapeño to start, figuring I could always jack up the heat later. Now, how to cook them?
Boiling the ingredients left the sauce watery, so I tried charring the tomatoes and jalapeño in a cast‑iron skillet. The dry heat sweetened and concentrated the tomatoes and intensified the jalapeño’s flavor. In the interest of efficiency, however, I decided to char under the broiler, and I halved the tomatoes so more of their watery insides could evaporate. For a bit more flavor, I added a clove of garlic and a wedge of onion to the pan as well.
I love pureed versions of salsa roja—they’re great for dispensing from squeeze bottles onto everything. So I opted to blend the tomatoes, chile, onion, and garlic with some salt until smooth. The sauce was good, but it lacked the brightness and depth of the finest examples I’ve had. A handful of cilantro helped, but not enough. A dried ancho chile would be just the thing to add a bit of raisin-y backbone. Dried chiles are usually softened in water before being blended, but waiting around for that wasn’t ideal. Then it occurred to me: Maybe I could hydrate the ancho and add brightness in a single step.
I tore the ancho into 1/2-inch pieces, which I put directly into the blender and ground to tiny specks. Then I added one of the raw tomatoes and pureed the mixture. I let the mixture sit while I broiled the rest of the ingredients. The fresh tomato pulp hydrated the ancho and added brightness to the sauce.
I still thought the sauce could use more depth, so I decided to add some minced chipotle chile in adobo sauce. The chipotle added a little more heat along with a welcome hint of smoke.
Now that I have a top-notch salsa roja, I’ll keep a perpetual supply in my refrigerator so I can put it on everything.